qemu.tests.balloon_check: Update the related params for balloon_check

Signed-off-by: NYiqiao Pu <ypu@redhat.com>

qemu/tests/cfg/balloon_check.cfg

@@ -4,6 +4,10 @@
     extra_params += " -balloon virtio"
     iterations = 5
     free_mem_cmd = cat /proc/meminfo |grep MemFree
+    Linux:
+        ratio = 1
+    Windows:
+        ratio = 0.5
     variants:
        - @base:
 
@@ -34,6 +38,7 @@
            sub_balloon_test_evict = "guest_suspend"
            guest_suspend_type = "disk"
            services_up_timeout = 30
+           qemu_quit_after_sub_case = yes
            # params: s3_support_chk_cmd, s3_bg_program_setup_cmd,
            # s3_bg_program_chk_cmd, s3_bg_program_kill_cmd, s3_log_chk_cmd,
            # s3_start_cmd and services_up_timeout are set in guest-os.cfg